Refrigerating apparatus.



No. 769,110. PATENTEDAUG. so, 1904.' J. PATTBNf REPRIG'BRATING gPPARATUs.

APPLICATION lIEILHI) 00T. .10, 1900.V

H0 MODEL. SBHEETS-BHEET 1. V

Inv E11-Ln: Fu-

fij,

Attn Hna- .4 5 i PATENTBD AUG. 3o, 1904.

J. PA TTBN. REFRIGERATING APPARATUS.

APPLICATION FILED OOT.10, 1900.

3 SHEETS-SHEET 2.

N0 MODEL.

No. 700,110. PATPNTPD AUG. 30, 1004. 1 J. PATTPN.v f

RPPRIGPRAPING APPARATUS.

APPLICATION FILED 00T. 10, 1900.

No MODEL.

3 SHEETS-SHEET 3.

UNITED STATES atented August 1904.:Y

PATENT OFFICE.

JOHN PATTEN, OF BALTIMORE, MARYLAND, ASSIGNOR TO PATTEN VACUUM ICE MACHINE COMPANY, OF BALTIMORE, MARYLAND,

A CORPORATION OF WEST VIRGINIA.

REFRIGERATING APPARATUS.

SPECIFICATION forming part of' Letters Patent No. 769,110, dated AugustO, 1904.

Application filed October 10, 1900. Serial No. 32,559. (No model.)

T a/ZZ whom t may concern.-

' Baltimore, in the State of Maryland, have incarried far enough into ice.

pump or vapor-exhauster of moderate dimenvented certain new and useful Improvements in Refrigerating Apparatus, of which the following is a specification. i

This invention comprises improvements in that class'of refrigerating apparatus in which water is cooled or frozen by subjecting it to the influence of a high vacuum. The rapid evaporation thus produced deprives the water of its heat and converts it if the process be In this class of apparatus a vacuum is created by means of an air or vacuum pump connected with the chamber containing the water to be frozen. The evaporation of the water is so rapid, however, that a high vacuum cannot be maintained without exposing the vapor from the freezingchamber to the action of a substancewhich has such an aiiinity for water thatl it will absorb a large part of aqueous water n vacuo. By the use of such a substance itfbecomes practicable to maintain a high vacuum continuously in a chamberI which is being constantly supplied with Water by means of a vacuum- 1 sions. The absorbent material must be continuously changed-that is, the dilute material which has performed its work and-absorbed a quantity of vapor must be drawn off and re-.

placed by concentrated material. It is customary to provide apparatus for continuously concentrating the absorbent and returning it to the absorber vessels.

, I have found that potassium hydroxid (KOIrDin solution can be utilized in this class of refrigerating apparatus in place of sulfuric i acid, which has heretofore been commonly used, and that this potassium hydroXid has a number ofV advantages over sulfuric acid. The

principal advantage is that the potassium hydroxid does not attack iron, and it can therefore be circulated through iron pipes and vessels and concentrated in an ordinary iron boilerl without any protective lining. This substance is introduced into the absorber vessels asa strong solution capable of'absorbing a' considerable quantity of vapor. The weak solution is pumped off from the absorber to a concentrating-boiler and again returned after concentration to the absorber. It can be concentrated and diluted alternately for an indeiinite length of time without deteriorating, and the apparatus for its use is very much cheaper than that required in utilizing sulfuric acid' for the same purpose.v

lapparatus being shown in side elevation.

Fig. 2 is an enlarged side elevation of the absorbers. Fig. 3 is a plan of the same, Figs. 2 and 3' being partly in section; and Fig. lis aview, partly in section, of a portion of the -plant in which the water suppliedto the freezing-chamber is purified.

Referring to the drawings, ldesignates a freezing-chamber, of which any desired numbermay be employed, according to the' size of the plant, two being shown in Fig. l. The freezing chamber or chambers communicate with a vapor tube or duct 2, through which vapor is conducted to the absorbers 3, A, and 5. These absorbers each consist of a cylindrical shell, within which are riveted or otherwise suitably secured transverse headplates 6 6, to which a series of tubes 7 'are united. The heads 6 6 and'tubes 7 may be connected together and to the cylindrical shell in the same manner as tubes are fastened in the tube-heads and such heads secured to the cylinders of vertical steam-boilers. The vapor-duct 2 communicates with the first two of the absorbers and is provided with an interior partition 8 between the absorbers 45, so that absorbers 3 l and can only reach the other The absorbing liquid passes from the conl centrators 11 through a pipe 12 and a "heatexchanger 13 into a tank or receptacle 14. The concentrators llmay be of very simple construction, consisting merely of a furnace or heating-chamber and a boiler arranged above said heater. No special arrangement of piping is required in constructing a concentrator for use with such an absorbing' liquid as I employ; but the upper portion of the concentrator 11 may be constructed as an ordinary hot-water boiler.

The heat-exchanger 13 consists of a cylin- A drical shell having a series of vertical tubes arranged 'therein and supported by transverse heads extending across the shell between its ends. The heated liquid passing downwardly through the pipe 12 passes through these tubes, and the dilute or weakened Huid passing from the absorbers to the concentrators passes around said tubes. The strongly-concentrated potassium hydroxid will solidify if suddenly cooled, and to avoid this I allow it to enter the receptacle or vat 14 while warm and also provide within said vat a stirrer or agitator 15, so that all of the potassium hydroxid will be dissolved in the water with which it'is mixed. The absorbing liquid is drawn from said vat 15 through a pipe 16 by means of a pump 17 and from said pump passes through suitable pipes 18 into distributing devices arranged within the absorbers 3 4 above the tubes 7 therein. Each of these distributers consists of a funnel-like member 19, into which the pipe 18 extends and which is provided at its lower end with a series of radial arms 20, having a series of perforations in their lower sides or faces. The distributer is suitably secured to a shaft 21, journaled in bearings in the tube-head 6 of the absorber and the vaporduct 2, and to the upper end of said shaft is secured a pulley 22, by means of which the distributer can be revolved.

The apertures or openings formed in the arms 2O of the distributing-nozzle or spraying device are arranged at such an angle that the liquid escaping therefrom is sprayed against opposite sides of the inner surface of the tubes 7 as said nozzle is revolved, and the absorbing liquid thus flows down the inner surfaces of said tubes. The tubes 7 are kept cool by water which is circulated through the body of the absorber between the heads 6 6 and about said tubes. In the constructionillustrated in the accompanying drawings such cooling waand passes from said absorber to th'e absorber 4 through a pipe 24 and from the absorber 4 to the absorber 3 through a pipe 25, escaping from the last said absorber through an outlet 26, which communicates with the condensers 27 of the vacuum apparatus. It will be uuderstood that the pump 17 simultaneously i supplies the funnels 19 of both absorbers 3 4, and by reference to Fig. 2 it will be seen that the partially-diluted absorbing liquid escaping from the tubes 7 in the absorber 3 is conducted into the vat or tank 14 to maintain the solution therein of the proper strength. The absorbing liquid that passes thrcugh the tubes7 of the absorber 4 is by means of a pump 28 forced into the funnel of the rotatable nozzle or spray device in absorber 5. After passing through the tubes of this absorber such liquid is by means of pump 29 delivered to the heat-exchanger 13,entering said exchanger through a pipe 30 and leaving the same through a pipe 31. Said pipes 30 31 are branches of a main pipe 32, that leads from the duct 33, communicating with the pump 29, to the concentrators 11, wherein the liquid is heated and from which the escaping vapor is conducted through pipes 34 and a drum 35 to the condensers 27. The heated and concentrated liquid passes, as before described, back to the heat-exchanger and vat 14 through the pipe 12. Suitable baffle-plates may be arranged within the drum 35 to obstruct the passage of any liquid from the concentrators to the condensers of the vacuum apparatus. An auxiliary exhaust or vacuum-pump 36 is connected with the main exhauster 10L and with the condensers 27, both of said exhausters or pumps, as well as the pump or exhauster 37 for maintaining a vacuum in the freezingchambers 1, being operated by steam generated in a boiler 38. The water condensed in the condensers .27 is conducted through apipe 39 into a well 40.

Another advantage attained by the use of a solution of potassium hydroxid as a vapor absorbent is that notwithstanding the great affinity of KOH for water I have found that very little heat is developed by combining the two. When apound of water-vapor is absorbed by sulfuric acid, I ind that about two hundred units of heat are developed over and above whatis known as the latent heat of vaporization or condensation. When an equal amount of vapor is absorbed by KOH, the additional heat developed is so small that it is scarcely perceptible. When sulfuric acid is used as an absorbent for the entire thousand units of heat for every pound of water-vapor which leaves the freezing-chamber, I lind that twelve hundred heat units are developed in the absorber, while when KOH is used only the amount which is carried from the freezingchambers appears as sensible heat in the absorber. I am thereby enabled to use about ter enters the absorber 5 through a pipe 23 65 IOO IIO

twenty per cent. less cooling-water in tlie absorbers thanwould b'e required if sulfuric acid were employed. I also nd a like advantage in the concentrators-that is, 'I find that it requires about twenty per cent. more heat to' vaporize a pound of water out of sulfuric acid than is required to vaporize the same amount out of a solution of KOI-I.

As is vwell known, potassium hydroXid (KOH) has a strong aiiinity for carbonic acid (CO2), forming a carbonate when they are chemically united. Therefore in order to provide a successful vacuum refrigerating plant in which potassium hydroXid is employed as the vapor.v absorbent it is necessary to remove carbonic acid from the water before freezing the same, and I accomplish this in the manner rectlyto the vacuum-pump, their volume would be so'great as to necessitate the employment of an undesirably large pump. Therefore in order to reduce the volume of such vaporit is passed through the condenser 42 from which the carbonic acid and other gases pass on tothe vacuum-pump through the pipe 43.

In order to condense the vapor, it isnecessary4 to maintain the conduits or ,passages through which the vapor passes in the condenser 42' at a low temperature. This I accomplish by surrounding the tubes 47 within said condenser with water which is exposed to the freezing vacuum. as the central portion of the condenser above said tubes communicates througha pipe 44 with the'main vaporduct 2. The passage of vapor from the condenser through this ',duct 44 is retarded and the desired pressure maintained in the con-A denser 42 by means of a valve 45. The water to be frozen enters the tank 41 through a sup- Aply-pipe 46, havingytherein avalve which is controlled by a iioat 46, and is broken linto a comparatively nfine spray-by suitable baffleplates and exposed to the action of the vacuf um as above described. The cooled water supply of water according to the demands and maintains the water around the cooling-tubes 47 at a constant level. vWhen the water is deprived of the. carbonic, acid, certain metallic salts contained therein are precipitated,which renders it slightly turbid. The particles not in solution are filtered out by a filter 50, and the purified water passes onto the freezing tank or tanksv through suitable flexible conductors 52,k a meter 51 for Iindicating the amount of water admitted. to each tank being preferably interposed between the filter and iiexible pipe. This arrangement of partsl find will eliminate practically all of thejcarbonic acid from the water and avoid .converting the potassium hydroXid into a carbonate of the same. A small percentage of the-carbonate of .potassium in lthe water would not be very objectionable, as said carbonate is an absorbent of about the same power as chlorid of calcium. A If after the plant has been running for some time under conditions which admit of the formation of small quantities of carbonate of potassium hydroXid .fand the percentage of such carbonate becomes great enough to deteriorate the absorbing power of the compound, the latter can be diluted with water and treated with .calcium hydroxid, which will take up the carbonic acid, forming carbonate of lime and restoring the compound to its original strength.r

e By' reference to Fig. 2 -it will be seen that the pipe 12, through which the absorbing compound passes from the concentrators 11, is

provided above the heat-exchanger 13 with a steam -jacket 12. This prevents thcrstrong concentrated fluid from solidifying before it reaches the mixing-tank, and in some cases the use of the heat-exchangercanbe dispensed with, theY liquid passing from the absorber 5 directly through the duct 32 to the concentrator without passing through the intermediate heat-exchanger.

Having` described my invention, what I claim as new, and desire to secure byLetters Patent, is v 1. Inavacuum refrigerating apparatus, the combination of a freezing-chamber, an absorber arranged to receive vapor from said freezing-chamber, a rotatable vspraying device mounted within said absorber, a concentrator for the absorbing fluid, a vat or tank for receiving the heated liquid from the concentrator, a stirrer within said tank, and a pump for supplying said rotatable spraying device with liquid from said tank, substantially'as described.

2. Ina vacuum refrigerating apparatus, the combination of a freezing-chamber, an absorber arranged to receive vapor from said freezing-chamber, a rotatable spraying device mounted within said absorber, aconcentrator` for the absorbing fluid, a vat or tank for receiving the heated liquid from the concentrator, means for supplying a portion of weak solution to said tank, a stirrer within said tank for mixing the concentrated and the IOO IIO

weak solutions, and a pump for supplying said rotatable spraying device with liquid from said tank, substantially as described.

3. In a vacuum refrigerating apparatus, the combination of a freezing-chamber, a series of absorbers, a duct for conducting vapor from the freezing-chamberto said absorbers and having an interior partition whereby direct communication between the freezingchamber and one of said absorbers is prevented, spraying devices arranged within each absorber, a concentrator for the absorbing solution, a tank or vat arranged to receive the absorbing liquid from said concentrator, a pump for forcing the absorbing liquid from said tank to the spraying device of an absorber between the transverse partition in the vapor-duct and the freezing-chamber', the liquid escaping from said absorber being reconducted to said tank or vat, a pump for supplying an absorber on the opposite side of the partition in the vapor-duct from the freezingchamber with the absorbing liquid and a pump for supplying the concentrator with liquid escaping from the last absorber in the series.

4. In avacuum refrigerating apparatus, the combination of a freezing-chamber, an absorber, a duct for conducting vapor from said chamber to said absorber, a concentrator for the absorbing fluid, a water-supply pipe, a tank receiving water from the pipe and connected with the freezing-chamber and with an exhaust-pump, a condenser interposed between said water-tank and the exhaust-pump, connections between the condenser and the duct which conducts vapor from the freezingchamber to the absorber and a pipe for conducting cooled water from said tank to the said condenser.

5. In a vacuum refrigerating apparatus, the combination of exhaustingmeans, a condenser comprising a series of tubes surrounded by water,said water being in communication with the exhausting means whereby it is cooled by evaporation, means for maintaining said water at a constant level, and a water-purifying tank in communication with the exhausting means, the gases and vapor freni said purifying-tank being conducted through the said condenser whereby the vapor is liquelied and separated from the gases.

6. In a vacuum refrigerating apparatus, the combination or' exhausting means, a condenser comprising a series of tubes surrounded by a water-chamber, a pipe leading from said chamber to the exhausting means, a checkvalve in said pipe, lmeans for automatically regulating the supply of water to said chamber, a water-purifying tank, connections from the water-purifying tank to the condenser' tubes, and connections from the condensertubes to the exhausting means, the gases and vapor from said purifying-tank being conducted through the said condenser, whereby the vapor is liquefied and separated from the gases.

In testimony whereofl I aiiix my signature in presence of two witnesses.

JOHN rA'r'EN.

Witnesses:

FELIX R. SULLIVAN, Louis A. KATZENBERGER. 

